System Considerations and FMCW Radar Transceiver for Breast Cancer Detection

Breast cancer detection with radar systems is an attractive alternative to conventional X-ray mammography. There are numerous publications that deal with this topic discussing the use of frequencies up to the millimeter wave range. However, one aspect that is often neglected is that human tissue differs from person to person and therefore cannot be described by a single material model. In this paper we show that a radar system for breast cancer detection that should be applicable to a large number of patients must be implemented in the microwave range. We present how an FMCW radar system with an adjustable analog baseband (ABB) can be used to compensate for the differences in permittivity. Moreover we present an RF front-end including transceiver and PLL which is realized with off-the-shelf components on a PCB. The RF front-end offers a bandwidth of 6 - 14 GHz which corresponds to a range resolution of around 8 mm, a variable TX output power up to +20 dBm and a conversion gain of 19 dB. The DSB noise figure was measured to be 4.7 dB at 6 GHz. Our results show that hardware for breast cancer detection with radar systems does not require expensive and bulky RF laboratory equipment.